Instrumentos para la recolección de datos

Where roofs or level surfaces are compartmentalised by structural features which could have the effect of restricting the free flow of smoke, the detectors shall be located so that early detection is ensured, subject to the following for point-type detectors (see Figure 9):

(a) For areas with ceiling height equal to or greater than 4 m and beam depth exceeding 100 mm (see Area 4, Figure 9), detectors shall be mounted on the underside of the beams and spaced in accordance with 2.8.3.3 and 2.8.3.4.

NOTE – Additional detectors shall be provided in interbeam area in cases where the interbeam area is so large that the spacing of detectors located on the underside of beams does not comply with 2.8.3.3 and 2.8.3.4.

(b) For areas with ceiling height greater than 2 m but not exceeding 4 m, beam depth exceeding 300 mm (see Area 3, Figure 9) and the interbeam area less than 4 m², detectors shall be mounted on the underside of the beams and spaced in accordance with 2.8.3.6.

(c) For areas such as item (b) above, where the interbeam area is equal to or greater than 4 m², detectors shall be mounted in each interbeam area (see Area 3, Figure 9).

(d) For areas with ceiling height not exceeding 4 m and beam depth not exceeding 300 mm (see Area 1, Figure 9), the spacing of the detectors shall be in accordance with 2.8.3.3 and 2.8.3.4.

(e) For areas with ceiling height not exceeding 2 m and beam depth exceeding 300 mm (see Area 2, Figure 9), the spacing of detectors shall be in accordance with 2.8.3.3 and 2.8.3.4.

NOTE – Where airflow reduces the response of the detector located in these areas, the detectors should be relocated in a more favourable position. Nevertheless, the spacing requirements of the above clauses should not be exceeded.

2.8.3.6 Reduced spacing

For all types of smoke detector, closer spacing may be required to take account of special characteristics of the protected area. The distance between detectors shall not exceed 7 m in the following areas where:

(a) the ceiling height is greater than 2 m but not exceeding 4 m, the beam depth exceeding 300 mm and the interbeam area less than 4 m²; or

(b) the number of air changes exceeds 15 per hour.

NOTE – For areas with high air velocities i.e. in excess of 3 m/s, the detector spacing may need to be further reduced or more sensitive detection equipment may need to be installed.

2.8.3.7 Spacing of detectors in concealed spaces

Concealed spaces for which protection is required under 1.4.1.3.1 shall be protected in accordance with the following:

(a) Concealed spaces with upper level surfaces in excess of 2 m high shall have detectors spaced in accordance with 2.8.3.3 and 2.8.3.4.

(b) For concealed spaces with upper level surface not exceeding 2 m high and having downward projections, such as beams and ducts, not exceeding 300 mm from the upper surface of the space, the spacing between detectors shall not exceed 15 m. Where the downward projections exceed 300 mm, the spacing of detectors shall be in accordance with 2.8.3.5.

(c) For concealed spaces with apices, the spacing between detectors in the longitudinal direction at the apex and sloping roof shall not exceed 10.2 m and 20.4 m respectively. On the sloping roof, the horizontal distances between rows parallel to the apex shall not exceed 10.2 m with the lowest row of detectors located not more than 10.2 m, measured horizontally towards the apex from a position where the vertical height, between the upper and lower surfaces of the space, is 800 mm. The longitudinal spaces between the detectors on the lower rows shall be arranged so that the detectors are spaced equally between the detectors on the adjacent rows (see Figure 5).

2.8.3.8 Detector mounting

The sensing element for ceiling mounted point-type detectors shall be not less than 25 mm and normally not more than 600 mm, below the ceiling or roof (see Figure 8).

Optical beam line-type smoke detectors shall be mounted not less than 300 mm and not more than 600 mm below the ceiling or roof. Additional optical beam line-type detectors should be installed in vertical shafts, e.g. atria and warehouse etc at lower levels (see Figure 8).

2.8.3.9 Arrangement of alarm zones

Not more than 20 smoke detectors shall be connected on a single alarm zone.

NOTE – Where a single alarm circuit is connected with more than 20 point-type smoke detectors, then means shall be specified and provided which ensure that a short circuit or an interruption in this detection alarm circuit does not prevent the indication of a fire alarm from more than 20 point-type smoke detectors.

(a) Spacing for open areas

(b) Spacing for corridors NOTE – Smoke detector spacing in corridors are the same as general areas.

Dimensions in millimetres

Figure 4 – Typical smoke detector spacing – Flat ceilings 10 200

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Figure 5 – Point-type smoke detector locations for concealed spaces with apex and sloping roof

NOTE 1 Alternate rows offset.

NOTE 2 See 2.8.3.7 (c).

NOTE 3 Lowest row measurement taken from 800 mm height.

Dimensions in millimetres

NOTE 1 – Lowest row measurement taken from 800 mm height applies to concealed spaces only.

NOTE 2 – Arrangement of siting of transmitter / receiver position shall be in accordance to the manufacturer’s recommendation.

Dimensions in millimetres

Figure 6 – Typical beam-type smoke detector locations for sloping surfaces 14 000

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(a) Unequal slope ceiling or roof (b) Sawtooth ceiling or roof

(c) Equal slope ceiling or roof

(d) Louvred ceiling or roof with louvred riser (e) Ceiling or roof with skylight

NOTE – Detector always on side with least slope.

Dimensions in millimetres

Figure 7 (in part) – Design criteria for point-type and beam-type smoke detectors located at apex of ceiling or roof

In document Imaginarios y constructos sociales del TDAH en el contexto educativo bogotano Natalia Rojas Cadena Juana Valentina Peña Bautista Pontificia Universidad Javeriana Facultad de Comunicación y Lenguaje Licenciatura en Lenguas Modernas Bogotá, D.C. 2022 (página 39-43)